Electron discharge device



May 10, 193s.

D. A. s. HALE ET AL ELECTRON DISCHARGE DEVICE Filed Jaml 9l 1936 MLRONC//NvENro/es: DASH/41.5

ATTORNEY Patented May 10, 1938 UNITED siarss 2,117,0til

PATENT OFFICE ELECTRON DISCHARGE DEVICE poration oi New York ApplicationJanuary 9, 1936, Serial No. 58,317

7 Claims.

This invention relates to' electron discharge devices and moreparticularly to such devices capable of dissipating considerable heatduring operation.

An object of the invention is to secure an eiiicient electrode structurefor an electron discharge device in which the output electrode issupported in such a manner that a large effective area is available fordissipating the heat energy consumed in the electrode.

Another object of the invention is to insure an eiective and inexpensivecoupling between connected elements having different physicalcharacteristics in a discharge device so that transient deleteriouscauses do not break or fracture the electrode.

A further object of the invention is to facilitate the eliicientassembly of the discharge device by proportioning the elements so thatthey may be fabricated with dispatch by unskilled labor.

In accordance with the general aspects of the invention, an electrode,such as an anode, is formed of a friable mass material, such asgraphite, with parallel hanged portions which extend outwardly from thesurface of the anode. A metallic post or channel member is situatedbetween the flanged portions and a locking member extends through thehanged portions and the channel member to secure the anode in positionin a unit with other cooperating electrodes, such as a cathode and acontrol electrode.

According to a specific aspect of the invention, the locking membercomprises a pair of wire pins which have straight portions extendingthrough the channel walls adjacent the parallel flange portions of theanode and arcuate portions which intersect in the center of the channelmember and are preferably Welded together at the point of intersection.In this arrangement the tight fit of the straight portions of the pinsin the graphite mass of the anode flanges provides a rigid mounting forthe anode and the slight curvature of the pins in the anode angesreenforced by the walls of the channel member forms a wedge for the pinsto avoid a loose connection. Furthermore, the welding of the pins at theintersection of the arcuate portions facilitates the assembly of theelectrode unit and provides an eicient and inexpensive connector for thesupport of the anode. A straight pin may be used for the connector withthe intermediate portion provided with an offset notch to lock the pinin position.

In accordance with a further modification of the invention, a single pinextends through the flanges of the anode and the adjacent channel (Cl.Z50-275) Walls and is surrounded by an intermediate metallic sleeve, thesleeve and pin being welded together at a central point. A modificationof the latter arrangement comprises a pair of headed pins which areinserted in the flanges of the anode and the channel walls from oppositedirections and joined by a sleeve interposed between the channel walls.

These and other features of the invention will be apparent from aperusal of the following description when read in connection with theaccompanying drawing:

Fig. l is a perspective View in elevation of an electron dischargedevice made in accordance with this invention and having a portion ofthe enclosing vessel and the output electrode broken away to show theinternal elements of the structural assembly;

Fig. 1A is an enlarged view in cross-section of the detail assembly ofthe anode structure taken on the line A-A of Fig. 1;

Fig. 2 is a perspective view from a different angle of the principalelements involved in this invention as applied to Fig. l, andillustrating the conguration of the output electrode and the supportingassembly;

Fig. 3 is an exploded perspective view of the anode and channel membersof this invention showing the prealignment of the elements to facilitateassembly;

Fig. 4 is a fragmentary view of the elements of the anode structureshowing a modification of the locking pin assembly according to thisinvention;

Fig. 5 shows a cross-sectional View of the anode structure andillustrates another modified form of locking member for connecting theanode to the channel members;

Fig. 6 is a detailed perspective view of the lockling member assemblyshown in Fig. 5; and

Fig. '7 illustrates another form of locking member for uniting the anodeto the channel members in which a central sleeve is telescoped ovei` theprojecting ends of contraposed pins when assembled in accordance withthis invention.

This invention in one of its aspects may be i adapted to a structuralassembly disclosed and claimed in our Patent 2,019,492, issued November5, 1935.

The discharge device comprising an enclosing vessel Ill having aninwardly projecting cylindrical stem II and an inner coaxial stem I2terminating in a press I3, the inner stem being provided with aninternal outwardly extending tubulation I4 which forms the exhaust tubeof the device. rl'he stems I I and I2 and also the enclosing vessel Illpreferably are formed of a borosilicate glass having high mechanical anddielectric strength and low coefficient of expansion, such as Nonex. Aninsulating cup-shaped base I5 is secured to the end of the enclosingvessel adjacent the stems and carries a plurality of terminals or prongsI6.

The electrode unit of the discharge device is completely supported fromthe cylindrical stern I I by a pair of spaced bands or collars I'I and.

I8 which are secured to the stem by clamping .bolts and nuts. Thesebands are fastened to a pair of parallel inverted U-shaped frames I9 and20 which extend above the edge of the cylindrical stem and form a basefor a plurality of supporting members connected to the electrode unit.Each frame carries two pairs of converging braces 2| and 22 which arewelded to the frames and extend upwardly to a pair of channel-shapedmetallic support posts or members 23 and 24. The braces are mechanicallylocked to the channel members by inserting the ends thereof throughapertures in the side walls of the channel members and crimping the endsinto engagement with the channel walls as shown at 25, in Fig. 2.

The channel posts form the rigid upright supports of the electrode unitand are arranged in parallel relation to the axis of the vessel. Theseposts are provided with integral flanges or extensions 26 at oppositeends which are bent up to close the ends of the channel posts. A pair ofcross-shaped insulating members 21 and 29 are positioned on the endanges and are rigidly fixed thereto by a metallic rivet 28 which isinserted through the insulating member, such as 29, shown in Fig. 1A,and extends through an oversize aperture in the flange 2. The rivet 23is secured to the assembly by placing a washer 28A over the end of therivet and spinning over the rivet. This assembly avoids placing unduestrain on the graphite anode and the insulating member duringfabrication since the elements may be easily aligned due to theclearance provided by the oversize aperture in the channel post flange.The insulating members serve as spacers and supporting members for acontrol electrode or grid 39 and a double M-shaped filamentary cathode3|.

The control electrode or grid 39 is in the form of a continuous helicalwire having the configuration of a flattened cylinder and is supportedbetween the insulating members 28 and 29 by upright posts or rods 32 and33 which are welded to successive turns of the helical wire. The grid39is held in normal relation between the insulating lmembers 28 and 29by the leading-in wire 34 extending from the press 3, the wire 34 beingattached to the upright rod 32 of the grid below the insulating spacer29 and at the other end is connected to one of the terminal prongs I6 onthe base I5.

The ends of the preformed filamentary cathode 3| are secured to hookmembers 35 while the mid-point of the filament is attached to anotherhcok member extending through the insulating member 29, the end hooksbeing attached to arms 36 of a tie wire extending below the insulator 29to which the center hook is also attached. The centers of the twoIVI-shaped sectons of the cathode are secured to separate hooks 31 whichare held in position by anchor wires in the insulator member 29 and theanchor wires are connected to leading-in wires 38 and 39 which extendfrom the press |3 and are connected to suitable terminals on the base ofthe device.

The lamentary cathode 3| is held under suit able tension by a number ofhook members 4D engaging the' bights of the formed cathode, the hookmembers being provided with elongated Shanks which extend through theinsulating member 28, and individual compression springs 4| are securedto an intermediate point of t .e

shank of each hook member. In order to maintain the ilamentary cathodein a medial plane, an insulating guiding strip 42 is supported above theinsulating member 28 by a pair of pins or posts 43. This guiding stripis provided with a number of elongated slots through which the free endsof the hooks 40 extend and limit the movement cf the hooks to a singleplane.

The power or output ratingv of electron discharge devices necessitatesthe employment of large electrode surfaces. Furthermore, the hightemperature operation and large effective area of the filamentarycathode cause considerable heat radiation. These factors imposeconsiderable strain on a sheet metal electrode surrounding the cathodeand grid. Since the heat energy is absorbed by the output electrode itis evident that if the radiation constant of the electrode is not highenough considerable damage can be caused due to buckling, or strains maybe developed which endanger the relationship of other elements in thedevice. Furthermore, the buckling effect may alter the internalresistance and capacitance characteristics of the device to such anextent that the efficiency of the device is considerably impaired. Thesedefects are materiallly overcome by employing a more stable material forthe output electrode which is capable of dls sipating the heat energytransmitted to it with a greater eiciency'than a metallic surface. Ithas been found that a friable material, such as. graphite, which has ahigh black-body constant, is admirably suited to this task. The use ofthis material heretofore has been handicapped by certain inherentcharacteristics and the dominant drawback of this material is itsbrittle tex- 2 ture which causes it to fracture when subjected tomechanical strains.

In accordance with this invention, graphite is used as the anodestructure to utilize the exceptional qualities of this material and theanode is rigidly fabricated in the electrode unit without subjecting thefriable material to mechanical strain. This is accomplished by formingthe anode 44 of a friable material, such as graphite,

either molded from a plastic mass or machined2 from a solid block into aconfiguration simulating a flattened cylinder having parallel side wallsand small diameter end portions to correspond with the configuration ofthe control electrode 30. The graphite anode is also provided with twoparallel outwardly extending flanged portions 45 which extend from eachouter parallel surface of the anode and are formed integra-l therewithas shown more clearly in Fig. 5. These flanges extend from the upperedges of the anode 'T and terminate slightly above the point where themechanical joint 25 is made between the braces 22 and the side walls ofthe channel member 23 as shown in Figs. 1 and 2. The flanges 45 areinterspaced on the anode structure sufficient to receive the channelmembers 23 so that the side walls 24 of the channel members abutagainst; the inner surfaces of the flanges 45. The flanges are alsodrilled to correspond with the apertures 46 in the side walls 24 of thechannel member 23. l'

A large portion of the flat area of the channel members 23 is out awayin the form of elongated slots 4l to expose a greater area of the anodesurface, and thereby increase the heat radiation of the anode.

The anode 44 is rigidly secured to the channel members 23, in accordancewith one embodimentl of the invention, by metallic locking members orwire pins 48 and 49 which form connectors between the flanged portion 45of the anode and the side walls 24 of the channel members. These pinsare provided with a short, straight portion which extends through theflange 45 of the anode and the remaining portion of the pin is curveddownwardly in an arcuate form so that the corresponding pins 48 and 49converge at the center of the channel member to provide a cruciformjoint which may be conveniently welded at the point of intersection ofthe pins.

A method of fabricating the anode with the remaining structure of theelectrode unit consists in placing each channel member in the spacebetween the flanged portions of the anode, then inserting each preformedpin through the aperture 46 in the channel member 23 and projecting thestraight portion of the pin through the aperture of the flange 45 on theanode, until the curved portion of the pin forms a wedge in the aperture46 in the channel member 23. When all the pins are in position,.thejunction points of the pins are welded to prevent displacement of thepins and to insure positive rigid contact of the pins with the channelwalls and the flanges of the anode. It will be noted that any strainproduced by the pin being inserted in the channel members and anges issustained by the side walls 24 of the channel members and this strain isnot imparted to the fragile flange portions 45 of the anode. Therefore,the locking pins of this invention, securely anchor the fragile anodematerial to the superstructure of the electrode unit without endangeringthe anode material by me chanical strain which might cause fracture ofthe anode.

In the form of locking connector previously described, it is necessaryto insert the locking pin through the side walls of the channel membersand then through -the anged portions of the anode due to the curvatureof the locking pins 48 and 49. While this assembly may be accomplishedwith dispatch even by an unskilled worker, another convenient connectormay be employed, as shown in Fig. 4. In this arrangement a straight pin50, shown in dotted line, may be inserted through the aligned holes inthe anode flanges and the channel walls and locked in position byoffsetting the center portion in a V-shaped conguration 5l.

Another pin arrangement shown in Fig. 6 also 'may be employed inassembling the cooperating elements in Fig. 5. In this arrangement ametallic sleeve 52 is positioned interjacent the side walls of thechannel member 23 in alignment with the apertures 46 therein and thecorrespending apertures in the flanges of the anode 44, and a straightpin 53 is threaded successively through the flange 45, channel wall 24,sleeve 52 and then through the remaining channel wall and anode flangeon the opposite side of the sleeve 52. 'I'he sleeve is then welded tothe locking pin 53 to form a rigid joint.

In another modification of the invention embodying a telescopic joint asabove described, the metallic sleeve 52 is positioned between the sidewalls of the channel member and contraposed locking pins 54 havingheaded terminations are inserted from opposed direction through theiiange portions 45 of the anode and into the metallic sleeve 52 wherethey are welded to form a rigid connection. In this arrangement it isnot essential to drive the pin 54 to such an extent that the heads ofthe pins are in contact with the anges 45 of the anode, since thelocking joint is determined by the welded connection with the sleeve 52and the pins do not exert any strain on the fragile iiange portions ofthe anode.

While various embodiments of the invention have been disclosed as abovedescribed, it is of course understood that various modications may bemade in the detailed structure of the assembly without departing fromthe scope of the invention as defined in the appended claims.

What is claimed is:

1. An electrode unit for an electron discharge device including anoutput electrode of a homogeneous mass having parallel integral fiangedportions projecting outwardly from the surface thereof, a metallicchannel support extending between said anged portions having the sidewalls thereof contiguous with said flanged portions, wire pins extendingthrough said flanged portions and channel side walls, and means. lockingsaid wire pins together to prevent movement of said output electrodewith respect to said channel support.

2. An electron discharge device electrode unit including an electrode oia mass of conducting `material having integral parallel flanged portionsextending from the surface thereof, a channel member interjacent saidflanged portions, and

anchor pins extending successively through said channel walls andflanged portions, said pins being welded together at a point out ofalignment with the portions extending through said channel members andanode.

3. An electron discharge device electrode unit comprising a graphiteelectrode having parallel flanged portions extending from the surfacethereof longitudinally of the electrode, a channel support interposedbetween said anged portions,

and arcuate pins interjacent said channel walls, said pins havingterminating ends extending through said walls and anode anged portions.

4. An electrode unit for an electron discharge device, comprising anoutput electrode of homogeneous graphite material having parallelflanged portions projecting outwardly from the surface thereof, ametallic channel support extending between said flanged portions havingthe side walls thereof contiguous with said anged portions, and itelescoped members having contraposed portions extending through saidflanged portions and channel walls.

5. An electron discharge device electrode unit including a graphite unithaving parallel anged portions extending from the surface thereof, ametallic support interposed between said anged portions, and connectingmembers joining said anged portions to said support, said membersintersecting each other at a medial point between said flanged portions.

6. An electron discharge device electrode unit including a graphiteanode having parallel flanged portions extending from the surfacethereof, a channel upright member interposed between said flangedportions, and locking means for said anode including a sleeveinterjacent said channel walls and contraposed anchor pins extendingthrough said anode ilanges and secured to said sleeve.

7. An electrode unit for an electron discharge deviceincluding agraphite anode of flattened cylindrical form having a pair of integralparallel flanges projecting outwardly from each outer parallel surfacethereof, a channel metallic support between each ,pair of ianges, eachof said supports having Walls abutting against the inner surfaces ofsaid flanges and a plane Wall having elongated cut-out portions abuttingthe outer sur- 10 face of said anode between said flanges, the

abutting flanges of said anode and the side walls of said supportshaving aligned apertures in a horizontal plane adjacent opposite ends ofsaid iianges, and pairs of arcuate pins interjacent the support sideWalls and divergently extending through said apertures,Y the pins ofeach pair being welded to maintain said pins in locking engagement withsaid flanges and supports.

DOUGLAS A. S. HALE.

VICTOR L. RONCI.

